Hydrofluorocarbon compositions

ABSTRACT

Refrigerant compositions include mixtures of difluoromethane and isobutane, butane, propylene or cyclopropane; pentafluoroethane and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane and propane; 1,1,1,2-tetrafluoroethane and cyclopropane; 1,1,1-trifluoroethane and DME or propylene; 1,1-difluoroethane and propane, isobutane, butane or cyclopropane; fluoroethane and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane and butane, cyclopropane, isobutane or propane.

FIELD OF THE INVENTION

This invention relates to refrigerant compositions that include a hydrofluorocarbon as a component. These compositions are also useful as cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as a refrigerant. Such refrigerants include dichlorodifluoromethane (CFC-12) and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds of fluorinated hydrocarbon refrigerants released into the atmosphere may adversely affect the stratospheric ozone layer. Although this proposition has not yet been completely established, there is a movement toward the control of the use and the production of certain chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under an international agreement.

Accordingly, there is a demand for the development of refrigerants that have a lower ozone depletion potential than existing refrigerants while still achieving an acceptable performance in refrigeration applications. Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCs and HCFCs since HFCs have no chlorine and therefore have zero ozone depletion potential.

In refrigeration applications, a refrigerant is often lost during operation through leaks in shaft seals, hose connections, soldered joints and broken lines. In addition, the refrigerant may be released to the atmosphere during maintenance procedures on refrigeration equipment. If the refrigerant is not a pure component or an azeotropic or azeotrope-like composition, the refrigerant composition may change when leaked or discharged to the atmosphere from the refrigeration equipment, which may cause the refrigerant to become flammable or to have poor refrigeration performance.

Accordingly, it is desirable to use as a refrigerant a single fluorinated hydrocarbon or an azeotropic or azeotrope-like composition that includes at least one fluorinated hydrocarbon.

Mixtures that include a fluorinated hydrocarbon may also be used as a cleaning agent or solvent to clean, for example, electronic circuit boards. It is desirable that the cleaning agents be azeotropic or azeotrope-like because in vapor degreasing operations the cleaning agent is generally redistilled and reused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinated hydrocarbon are also useful as blowing agents in the manufacture of closed-cell polyurethane, phenolic and thermoplastic foams, as propellants in aerosols, as heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids such as for heat pumps, inert media for polymerization reactions, fluids for removing particulates from metal surfaces, as carrier fluids that may be used, for example, to place a fine film of lubricant on metal parts, as buffing abrasive agents to remove buffing abrasive compounds from polished surfaces such as metal, as displacement drying agents for removing water, such as from jewelry or metal parts, as resist developers in conventional circuit manufacturing techniques including chlorine-type developing agents, or as strippers for photoresists when used with, for example, a chlorohydrocarbon such as 1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of refrigerant compositions of difluoromethane (HFC-32) and isobutane, butane, propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane; 1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane; 1,1,1-trifluoroethane (HFC-143a) and dimethyl ether (DME) or propylene; 1,1-difluoroethane (HFC-152a) and propane, isobutane, butane or cyclopropane; fluoroethane (HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane, isobutane or propane. These compositions are also useful as cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.

Further, the invention relates to the discovery of binary azeotropic or azeotrope-like compositions comprising effective amounts of difluoromethane (HFC-32) and isobutane, butane, propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane; 1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane; 1,1,1-trifluoroethane (HFC-143a) and propylene; 1,1-difluoroethane (HFC-152a) and propane, isobutane, butane and cyclopropane; fluoroethane (HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane, isobutane or propane to form an azeotropic or azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor pressure of liquid mixtures of HFC-32 and isobutane at 25° C.;

FIG. 2 is a graph of the vapor pressure of liquid mixtures of HFC-32 and butane at 25° C.;

FIG. 3 is a graph of the vapor pressure of liquid mixtures of HFC-32 and propylene at 25° C.;

FIG. 4 is a graph of the vapor pressure of liquid mixtures of HFC-32 and cyclopropane at 0° C.;

FIG. 5 is a graph of the vapor pressure of liquid mixtures of HFC-125 and propylene at 25° C.;

FIG. 6 is a graph of the vapor pressure of liquid mixtures of HFC-125 and cyclopropane at 0° C.;

FIG. 7 is a graph of the vapor pressure of liquid mixtures of HFC-134 and propane at 15° C.;

FIG. 8 is a graph of the vapor pressure of liquid mixtures of HFC-134a and cyclopropane at 0.01° C.;

FIG. 9 is a graph of the vapor pressure of liquid mixtures of HFC-143a and propylene at 25° C.;

FIG. 10 is a graph of the vapor pressure of liquid mixtures of HFC-152a and propane at 25° C.;

FIG. 11 is a graph of the vapor pressure of liquid mixtures of HFC-152a and isobutane at 25° C.;

FIG. 12 is a graph of the vapor pressure of liquid mixtures of HFC-152a and butane at 25° C.;

FIG. 13 is a graph of the vapor pressure of liquid mixtures of HFC-152a and cyclopropane at 25° C.;

FIG. 14 is a graph of the vapor pressure of liquid mixtures of HFC-161 and propane at 25° C.;

FIG. 15 is a graph of the vapor pressure of liquid mixtures of HFC-161 and cyclopropane at 25° C.;

FIG. 16 is a graph of the vapor pressure of liquid mixtures of HFC-227ca and butane at 25° C.;

FIG. 17 is a graph of the vapor pressure of liquid mixtures of HFC-227ca and cyclopropane at 25° C.;

FIG. 18 is a graph of the vapor pressure of liquid mixtures of HFC-227ca and DME at 25° C.;

FIG. 19 is a graph of the vapor pressure of liquid mixtures of HFC-227ca and isobutane at 25° C.;

FIG. 20 is a graph of the vapor pressure of liquid mixtures of HFC-227ca and propane at 25° C.;

FIG. 21 is a graph of the vapor pressure of liquid mixtures of HFC-227ea and butane at 25° C.;

FIG. 22 is a graph of the vapor pressure of liquid mixtures of HFC-227ea and cyclopropane at 25° C.;

FIG. 23 is a graph of the vapor pressure of liquid mixtures of HFC-227ea and isobutane at 25° C.; and

FIG. 24 is a graph of the vapor pressure of liquid mixtures of HFC-227ea and propane at 25° C.

DETAILED DESCRIPTION

The present invention relates to compositions of difluoromethane (HFC-32) and isobutane, butane, propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene and cyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane; 1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane; 1,1,1-trifluoroethane (HFC-143a) and dimethyl ether (DME) or propylene; 1,1-difluoroethane (HFC-152a) and propane, isobutane, butane and cyclopropane; fluoroethane (HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane, isobutane or propane.

The present invention also relates to the discovery of azeotropic or azeotrope-like compositions of effective amounts of difluoromethane (HFC-32) and isobutane, butane, propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane; 1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane; 1,1,1-trifluoroethane (HFC-143a) propylene; 1,1-difluoroethane (HFC-152a and propane, isobutane, butane and cyclopropane; fluoroethane (HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane, isobutane or propane to form an azeotropic or azeotrope-like composition.

By "azeotropic" composition is meant a constant boiling liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without compositional change. Constant boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, as compared with that of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, or substantially constant boiling, liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotrope-like composition is that the vapor produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without substantial composition change.

It is recognized in the art that a composition is azeotrope-like if, after 50 weight percent of the composition is removed such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is about 10 percent or less, when measured in absolute units. By absolute units, it is meant measurements of pressure and, for example, psia, atmospheres, bars, torr, dynes per square centimeter, millimeters of mercury, inches of water and other equivalent terms well known in the art. If an azeotrope is present, there is no difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed.

Therefore, included in this invention are compositions of effective amounts of difluoromethane (HFC-32) and isobutane, butane, propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane; 1,1,1,2-tetrafluoroethane (HFC134a ) and cyclopropane; 1,1,1-trifluoroethane (HFC-143a) and propylene; 1,1-difluoroethane (HFC-152a) and propane, isobutane, butane and cyclopropane; fluoroethane (HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane, isobutane or propane such that after 50 weight percent of an original composition is evaporated or boiled off to produce a remaining composition, the difference in the vapor pressure between the original composition and the remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range of compositions around the azeotrope that, for a maximum boiling azeotrope, have boiling points at a particular pressure higher than the pure components of the composition at that pressure and have vapor pressures lower at a particular temperature than the pure components of the composition at that temperature, and that, for a minimum boiling azeotrope, have boiling points at a particular pressure lower than the pure components of the composition at that pressure and have vapor pressures higher at a particular temperature than the pure components of the composition at that temperature. Boiling temperatures and vapor pressures above or below that of the pure components are caused by unexpected intermolecular forces between and among the molecules of the compositions, which can be a combination of repulsive and attractive forces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling point at a particular pressure, or a maximum or minimum vapor pressure at a particular temperature, may or may not be coextensive with the range of compositions that are substantially constant boiling. In those cases where the range of compositions that have maximum or minimum boiling temperatures at a particular pressure, or maximum or minimum vapor pressures at a particular temperature, are broader than the range of compositions that are substantially constant boiling according to the change in vapor pressure of the composition when 50 weight percent is evaporated, the unexpected intermolecular forces are nonetheless believed important in that the refrigerant compositions having those forces that are not substantially constant boiling may exhibit unexpected increases in the capacity or efficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the following vapor pressures at 25° C.

    ______________________________________                                         COMPONENTS        PSIA    KPA                                                  ______________________________________                                         HFC-32            246.7   1701                                                 HFC-125           199.1   1373                                                 HFC-134           76.1    525                                                  HFC-134a          98.3    677                                                  HFC-143a          180.6   1245                                                 HFC-152a          85.8    591                                                  HFC-161           130.2   898                                                  HFC-227ca         63.8    440                                                  HFC-227ea         66.6    459                                                  butane            35.2    243                                                  cyclopropane      105.0   724                                                  DME               85.7    591                                                  isobutane         50.5    348                                                  propane           137.8   950                                                  propylene         165.9   1144                                                 ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-like compositions of this invention comprise the following (all compositions are measured at 25° C.):

    ______________________________________                                                       WEIGHT RANGES  PREFERRED                                         COMPONENTS    (wt. %/wt/%)   (wt. %/wt. %)                                     ______________________________________                                         HFC-32/isobutane                                                                             61-99/1-39     70-99/1-30                                        HFC-32/butane 65-99/1-35     70-99/1-30                                        HFC-32/propylene                                                                             26-99/1-74     70-99/1-30                                        HFC-32/cyclopropane                                                                          54-99/1-46     54-99/1-46                                        HFC-125/propylene                                                                             1-99/1-99     60-99/1-40                                        HFC-125/cyclopropane                                                                         66-99/1-34     66-99/1-34                                        HFC-134/propane                                                                              1-75/25-99     30-75/25-70                                       HFC-134a/cyclopropane                                                                         1-99/1-99     50-99/1-50                                        HFC-143a/propylene                                                                            1-99/1-99     70-99/1-30                                        HFC-152a/propane                                                                             1-78/22-99     30-78/22-70                                       HFC-152a/isobutane                                                                           44-99/1-56     60-99/1-40                                        HFC-152a/butane                                                                              54-99/1-46     70-99/1-30                                        HFC-152a/cyclopropane                                                                         1-99/1-99     20-99/1-80                                        HFC-161/propane                                                                               1-99/1-99     20-99/1-80                                        HFC-161/cyclopropane                                                                          1-99/1-99     40-99/1-60                                        HFC-227ca/butane                                                                             61-99/1-39     70-99/1-30                                        HFC-227ca/    27-82/18-73    40-82/18-60                                       cyclopropane                                                                   HFC-227ca/DME  1-92/8-99     60-92/8-40                                        HFC-227ca/isobutane                                                                          53-92/8-47     60-92/8-40                                        HFC-227ca/propane                                                                            1-79/21-99     30-79/21-70                                       HFC-227ea/butane                                                                             61-99/1-39     70-99/1-30                                        HFC-227ea/    24-83/17-76    40-83/17-60                                       cyclopropane                                                                   HFC-227ea/isobutane                                                                          52-99/1-48     60-99/1-40                                        HFC-227ea/propane                                                                            1-79/21-99     40-79/21-60                                       ______________________________________                                    

For purposes of this invention, "effective amount" is defined as the amount of each component of the inventive compositions which, when combined, results in the formation of an azeotropic or azeotrope-like composition. This definition includes the amounts of each component, which amounts may vary depending on the pressure applied to the composition so long as the azeotropic or azeotrope-like compositions continue to exist at the different pressures, but with possible different boiling points.

Therefore, effective amount includes the amounts, such as may be expressed in weight percentages, of each component of the compositions of the instant invention which form azeotropic or azeotrope-like compositions at temperatures or pressures other than as described herein.

For the purposes of this discussion, azeotropic or constant-boiling is intended to mean also essentially azeotropic or essentially constant boiling. In other words, included within the meaning of these terms are not only the true azeotropes described above, but also other compositions containing the same components in different proportions, which are true azeotropes at other temperatures and pressures, as well as those equivalent compositions which are part of the same azeotropic system and are azeotrope-like in their properties. As is well recognized in this art, there is a range of compositions which contain the same components as the azeotrope, which will not only exhibit essentially equivalent properties for refrigeration and other applications, but which will also exhibit essentially equivalent properties to the true azeotropic composition in terms of constant boiling characteristics or tendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixture which may appear under many guises, depending upon the conditions chosen, by any of several criteria:

* The composition can be defined as an azeotrope of A, B, C (and D . . . ) since the very term "azeotrope" is at once both definitive and limitative, and requires that effective amounts of A, B, C (and D . . . ) for this unique composition of matter which is a constant boiling composition.

* It is well known by those skilled in the art, that, at different pressures, the composition of a given azeotrope will vary at least to some degree, and changes in pressure will also change, at least to some degree, the boiling point temperature. Thus, an azeotrope of A, B, C (and D . . . ) represents a unique type of relationship but with a variable composition which depends on temperature and/or pressure. Therefore, compositional ranges, rather than fixed compositions, are often used to define azeotropes.

* The composition can be defined as a particular weight percent relationship or mole percent relationship of A, B, C (and D . . . ), while recognizing that such specific values point out only one particular relationship and that in actuality, a series of such relationships, represented by A, B, C (and D . . . ) actually exist for a given azeotrope, varied by the influence of pressure.

* An azeotrope of A, B, C (and D . . . ) can be characterized by defining the compositions as an azeotrope characterized by a boiling point at a given pressure, thus giving identifying characteristics without unduly limiting the scope of the invention by a specific numerical composition, which is limited by and is only as accurate as the analytical equipment available.

The azeotrope or azeotrope-like compositions of the present invention can be prepared by any convenient method including mixing or combining the desired amounts. A preferred method is to weigh the desired component amounts and thereafter combine them in an appropriate container.

Specific examples illustrating the invention are given below. Unless otherwise stated therein, all percentages are by weight. It is to be understood that these examples are merely illustrative and in no way are to be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following composition is azeotropic. The temperature is 25° C.

    ______________________________________                                                               Vapor Press.                                             Composition    Weight Percents                                                                             psia     kPa                                       ______________________________________                                         HFC-32/isobutane                                                                              93.8/6.2     249.6    1721                                      HFC-32/butane  99.0/1.0     246.8    1702                                      HFC-32/propylene                                                                              81.0/19.0    261.5    1803                                      HFC-32/cyclopropane                                                                           85.2/14.8    260.6    1797                                      HFC-125/propylene                                                                             79.5/20.5    229.1    1580                                      HFC-125/cyclopropane                                                                          91.3/8.7     209.6    1445                                      HFC-134/propane                                                                               52.3/47.7    164.3    1132                                      HFC-134a/cyclopropane                                                                         65.5/34.5    137.5     948                                      HFC-143a/propylene                                                                            89.6/10.4    181.2    1249                                      HFC-152a/propane                                                                              45.9/54.1    155.1    1069                                      HFC-152a/isobutane                                                                            75.5/24.5     97.0     669                                      HFC-152a/butane                                                                               85.0/15.0     90.5     624                                      HFC-152a/cyclopropane                                                                         44.3/55.7    117.8     812                                      HFC-161/propane                                                                               44.5/55.5    161.2    1111                                      HFC-161/cyclopropane                                                                          63.4/36.6    140.8     971                                      HFC-227ca/butane                                                                              84.4/15.6     77.5     534                                      HFC-227ca/cyclopropane                                                                        55.8/44.2    126.5     872                                      HFC-227ca/DME  75.6/24.4    101.0     696                                      HFC-227ca/isobutane                                                                           76.8/23.2     90.0     621                                      HFC-227ca/propane                                                                             51.6/48.4    159.8    1102                                      HFC-227ea/butane                                                                              85.8/14.2     76.8     530                                      HFC-227ea/cyclopropane                                                                        55.2/44.8    125.1     863                                      HFC-227ea/isobutane                                                                           77.6/22.4     88.8     612                                      HFC-227ea/propane                                                                             50.4/49.6    157.4    1085                                      ______________________________________                                    

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial liquid composition at 25° C. The liquid, and the vapor above the liquid, are allowed to come to equilibrium, and the vapor pressure in the vessel is measured. Vapor is allowed to leak from the vessel, while the temperature is held constant at 25° C., until 50 weight percent of the initial charge is removed, at which time the vapor pressure of the composition remaining in the vessel is measured. The results are summarized below.

    __________________________________________________________________________     Refrigerant  0 wt % evaporated                                                                        50 wt % evaporated                                                                       0% change in                                  Composition  psia kPa  psia kPa  vapor pressure                                __________________________________________________________________________     HFC-32/isobutane                                                               93.8/6.2     249.6                                                                               1721 249.6                                                                               1721 0.0                                           99/1         247.8                                                                               1709 247.5                                                                               1706 0.1                                           70/30        240.8                                                                               1660 230.3                                                                               1588 4.4                                           60/40        234.8                                                                               1619 209.6                                                                               1445 10.7                                          61/39        235.5                                                                               1624 212.3                                                                               1464 9.9                                           HFC-32/butane                                                                  99.0/1.0     246.8                                                                               1702 246.8                                                                               1702 0.0                                           70/30        232.3                                                                               1602 217.4                                                                               1499 6.4                                           65/35        229.1                                                                               1580 206.6                                                                               1424 9.8                                           HFC-32/propylene                                                               81.0/19.0    261.5                                                                               1803 261.5                                                                               1803 0.0                                           99/1         248.8                                                                               1715 248.0                                                                               1710 0.3                                           70/30        259.3                                                                               1788 257.7                                                                               1777 0.6                                           60/40        254.3                                                                               1753 248.8                                                                               1715 2.2                                           50/50        246.7                                                                               1701 235.7                                                                               1625 4.5                                           40/60        236.6                                                                               1631 219.6                                                                               1514 7.2                                           30/70        223.8                                                                               1543 202.6                                                                               1397 9.5                                           29/71        222.3                                                                               1533 200.9                                                                               1385 9.6                                           27/73        219.3                                                                               1512 197.6                                                                               1362 9.9                                           26/74        217.8                                                                               1502 196.0                                                                               1351 10.0                                          HFC-32/cyclopropane                                                            85.2/14.8    260.6                                                                               1797 260.6                                                                               1797 0.0                                           99/1         249.3                                                                               1719 248.2                                                                               1711 0.4                                           60/40        250.5                                                                               1727 236.5                                                                               1631 5.6                                           54/46        246.0                                                                               1696 222.5                                                                               1534 9.6                                           53/47        245.2                                                                               1691 219.7                                                                               1515 10.4                                          HFC-125/propylene                                                              79.5/20.5    229.1                                                                               1580 229.1                                                                               1580 0.0                                           90/10        224.8                                                                               1550 222.4                                                                               1533 1.1                                           99/1         203.9                                                                               1406 201.8                                                                               1391 1.0                                           70/30        227.4                                                                               1568 225.9                                                                               1558 0.7                                           50/50        217.2                                                                               1498 206.5                                                                               1424 4.9                                           40/60        209.9                                                                               1447 194.1                                                                               1338 7.5                                           30/70        201.2                                                                               1387 183.1                                                                               1262 9.0                                           20/80        191.1                                                                               1318 174.8                                                                               1205 8.5                                           10/90        179.3                                                                               1236 169.3                                                                               1167 5.6                                            1/99        167.4                                                                               1154 166.2                                                                               1146 0.7                                           HFC-125/cyclopropane                                                           91.3/8.7     209.6                                                                               1445 209.6                                                                               1445 0.0                                           99/1         202.2                                                                               1394 201.3                                                                               1388 0.4                                           66/34        194.9                                                                               1344 176.5                                                                               1217 9.4                                           65/35        194.1                                                                               1338 174.2                                                                               1201 10.3                                          HFC-134/propane                                                                90/10        140.0                                                                                965  83.6                                                                                576 40.3                                          75.6/24.4    158.9                                                                               1095 143.0                                                                                986 10.0                                          52.3/47.7    164.3                                                                               1132 164.3                                                                               1132 0.0                                           25/75        157.3                                                                               1085 152.1                                                                               1049 3.3                                            1/99        138.5                                                                                955 137.8                                                                                950 0.5                                           HFC-134a/cyclopropane                                                          65.5/34.5    137.5                                                                                948 137.5                                                                                948 0.0                                           90/10        126.8                                                                                874 116.8                                                                                805 7.9                                           95/5         117.1                                                                                807 106.2                                                                                732 9.3                                           99/1         103.2                                                                                712  99.5                                                                                686 3.6                                           30/70        129.4                                                                                892 119.4                                                                                823 7.7                                           15/85        120.2                                                                                829 109.5                                                                                755 8.9                                           10/90        115.9                                                                                799 107.5                                                                                741 7.2                                            1/99        106.3                                                                                733 105.2                                                                                725 1.0                                           HFC-143a/propylene                                                             89.6/10.4    181.2                                                                               1249 181.2                                                                               1249 0.0                                           99/1         180.7                                                                               1246 180.7                                                                               1246 0.0                                           60/40        178.4                                                                               1230 178.1                                                                               1228 0.2                                           40/60        174.7                                                                               1205 174.2                                                                               1201 0.3                                           20/80        170.5                                                                               1176 170.0                                                                               1172 0.3                                            1/99        166.2                                                                               1146 166.1                                                                               1145 0.1                                           HFC-152a/propane                                                               45.9/54.1    155.1                                                                               1069 155.1                                                                               1069 0.0                                           60/40        153.7                                                                               1060 152.2                                                                               1049 1.0                                           70/30        151.0                                                                               1041 146.1                                                                               1007 3.2                                           78/22        147.5                                                                               1017 134.5                                                                                927 8.8                                           79/21        147.0                                                                               1014 131.9                                                                                909 10.3                                          30/70        153.2                                                                               1056 152.0                                                                               1048 0.8                                           20/80        149.9                                                                               1034 147.6                                                                               1018 1.5                                           10/90        144.8                                                                                998 142.6                                                                                983 1.5                                            1/99        138.6                                                                                956 138.2                                                                                953 0.3                                           HFC-152a/isobutane                                                             75.5/24.5     97.0                                                                                669  97.0                                                                                669 0.0                                           90/10         94.7                                                                                653  92.5                                                                                638 2.3                                           99/1          87.3                                                                                602  86.3                                                                                595 1.1                                           60/40         95.7                                                                                660  93.9                                                                                647 1.9                                           40/60         90.4                                                                                623  79.2                                                                                546 12.4                                          43/57         91.5                                                                                631  82.3                                                                                567 10.1                                          44/56         91.8                                                                                633  83.3                                                                                574 9.3                                           HFC-152a/butane                                                                85.0/15.0     90.5                                                                                624  90.5                                                                                624 0.0                                           95/5          88.9                                                                                613  88.2                                                                                608 0.8                                           99/1          86.6                                                                                597  86.2                                                                                594 0.5                                           70/30         89.0                                                                                614  87.4                                                                                603 1.8                                           60/40         87.1                                                                                601  82.4                                                                                568 5.4                                           53/47         85.3                                                                                588  76.7                                                                                529 10.1                                          54/46         85.6                                                                                590  77.6                                                                                535 9.3                                           HFC-152a/cyclopropane                                                          44.3/55.7    117.8                                                                                812 117.8                                                                                812 0.0                                           70/30        113.8                                                                                785 110.9                                                                                765 2.5                                           90/10        100.4                                                                                692  94.3                                                                                650 6.1                                           99/1          87.6                                                                                604  86.5                                                                                596 1.3                                           20/80        114.6                                                                                790 113.0                                                                                779 1.4                                            1/99        105.8                                                                                729 105.4                                                                                727 0.4                                           HFC-161/propane                                                                44.5/55.5    161.2                                                                               1111 161.2                                                                               1111 0.0                                           70/30        156.0                                                                               1076 153.2                                                                               1056 1.8                                           90/10        142.2                                                                                980 137.9                                                                                951 3.0                                           99/1         131.6                                                                                907 130.9                                                                                903 0.5                                           20/80        156.0                                                                               1076 153.2                                                                               1056 1.8                                            1/99        139.3                                                                                960 138.5                                                                                955 0.6                                           HFC-161/cyclopropane                                                           63.4/36.6    140.8                                                                                971 140.8                                                                                971 0.0                                           80/20        138.9                                                                                958 138.4                                                                                954 0.4                                           99/1         130.8                                                                                902 130.7                                                                                901 0.1                                           30/70        134.2                                                                                925 129.8                                                                                895 3.3                                           15/85        125.2                                                                                863 116.3                                                                                802 7.1                                           10/90        120.4                                                                                830 111.6                                                                                769 7.3                                            1/99        107.1                                                                                738 105.5                                                                                727 1.5                                           HFC-227ca/butane                                                               84.4/15.6     77.5                                                                                534  77.5                                                                                534 0.0                                           92/8          76.4                                                                                527  74.5                                                                                514 2.5                                           99/1          67.3                                                                                464  64.8                                                                                447 3.7                                           60/40         75.4                                                                                520  67.8                                                                                467 10.1                                          61/39         75.5                                                                                521  69.0                                                                                476 8.6                                           HFC-227ca/cyclopropane                                                         55.8/44.2    126.5                                                                                872 126.5                                                                                872 0.0                                           80/20        121.4                                                                                837 112.6                                                                                776 7.2                                           85/15        117.0                                                                                807 102.1                                                                                704 12.7                                          83/17        119.1                                                                                821 106.8                                                                                736 10.3                                          82/18        119.9                                                                                827 108.9                                                                                751 9.2                                           30/70        124.8                                                                                860 116.5                                                                                803 6.7                                           25/75        123.9                                                                                854 110.4                                                                                761 10.9                                          26/74        124.1                                                                                856 111.5                                                                                769 10.2                                          27/73        124.3                                                                                857 112.7                                                                                777 9.3                                           HFC-227ca/DME                                                                  75.6/24.4    101.0                                                                                696 101.0                                                                                696 0.0                                           90/10         98.1                                                                                676  94.3                                                                                650 3.9                                           92/8          96.9                                                                                668  90.0                                                                                621 7.1                                           93/7          96.1                                                                                663  86.1                                                                                594 10.4                                          40/60         95.1                                                                                656  92.7                                                                                639 2.5                                           20/80         90.3                                                                                623  88.5                                                                                610 2.1                                            1/99         85.9                                                                                 592                                                                                85.8                                                                                592 0.1                                           HFC-227ca/isobutane                                                            76.8/23.2     90.0                                                                                621  90.0                                                                                621 0.0                                           90/10         87.5                                                                                603  81.8                                                                                564 6.5                                           95/5          82.0                                                                                565  70.6                                                                                487 13.9                                          93/7          85.0                                                                                586  75.3                                                                                519 11.4                                          92/8          86.0                                                                                593  77.6                                                                                535 9.8                                           50/50         88.0                                                                                607  75.2                                                                                518 14.5                                          55/45         88.6                                                                                611  83.0                                                                                572 6.3                                           53/47         88.4                                                                                610  80.5                                                                                555 8.9                                           52/48         88.3                                                                                609  79.0                                                                                545 10.5                                          HFC-227ca/propane                                                              51.6/48.4    159.8                                                                               1102 159.8                                                                               1102 0.0                                           30/70        157.9                                                                               1089 152.1                                                                               1049 3.7                                           20/80        155.0                                                                               1069 143.8                                                                                991 7.2                                           15/85        152.6                                                                               1052 140.9                                                                                971 7.7                                           10/90        149.3                                                                               1029 139.2                                                                                960 6.8                                            1/99        139.4                                                                                961 137.9                                                                                951 1.1                                           80/20        153.6                                                                               1059 136.8                                                                                943 10.9                                          78/22        154.9                                                                               1068 142.2                                                                                980 8.2                                           79/21        154.3                                                                               1064 139.7                                                                                963 9.5                                           HFC-227ea/butane                                                               85.8/14.2     76.8                                                                                530  76.8                                                                                530 0.0                                           92/8          76.0                                                                                524  75.1                                                                                518 1.2                                           99/1          69.0                                                                                476  67.7                                                                                467 1.9                                           60/40         73.8                                                                                509  66.1                                                                                456 10.4                                          61/39         74.0                                                                                510  67.2                                                                                463 9.2                                           HFC-227ea/cyclopropane                                                         55.2/44.8    125.1                                                                                863 125.1                                                                                863 0.0                                           80/20        119.7                                                                                825 111.8                                                                                771 6.6                                           90/10        107.4                                                                                741  89.5                                                                                617 16.7                                          85/15        115.2                                                                                794 102.3                                                                                705 11.2                                          83/17        117.3                                                                                809 106.5                                                                                734 9.2                                           84/16        116.3                                                                                802 104.5                                                                                721 10.1                                          30/70        123.3                                                                                850 116.7                                                                                805 5.4                                           25/75        122.4                                                                                844 111.5                                                                                769 8.9                                           23/77        122.0                                                                                841 109.7                                                                                756 10.1                                          24/76        122.2                                                                                843 110.6                                                                                763 9.5                                           HFC-227ea/isobutane                                                            77.6/22.4     88.8                                                                                612  88.8                                                                                612 0.0                                           85/15         88.2                                                                                608  87.1                                                                                601 1.2                                           99/1          71.0                                                                                490  67.6                                                                                466 4.8                                           50/50         86.3                                                                                595  74.9                                                                                516 13.2                                          55/45         87.0                                                                                600  81.5                                                                                562 6.3                                           53/47         86.8                                                                                598  79.4                                                                                547 8.5                                           52/48         86.6                                                                                597  78.1                                                                                538 9.8                                           HFC-227ea/propane                                                              50.4/49.6    157.4                                                                               1085 157.4                                                                               1085 0.0                                           70/30        155.2                                                                               1070 150.8                                                                               1040 2.8                                           90/10        133.7                                                                                922  91.5                                                                                631 31.6                                          80/20        150.0                                                                               1034 133.6                                                                                921 10.9                                          79/21        150.8                                                                               1040 136.3                                                                                940 9.6                                           30/70        155.7                                                                               1074 151.4                                                                               1044 2.8                                           20/80        153.0                                                                               1055 144.3                                                                                995 5.7                                           10/90        147.8                                                                               1019 139.6                                                                                963 5.5                                            1/99        139.1                                                                                959 137.9                                                                                951 0.9                                           __________________________________________________________________________

The results of this Example show that these compositions are azeotropic or azeotrope-like because when 50 wt. % of an original composition is removed, the vapor pressure of the remaining composition is within about 10% of the vapor pressure of the original composition, at a temperature of 25° C.

EXAMPLE 3 Impact of Vapor Leakage at 0° C.

A leak test is performed on compositions of HFC-32 and cyclopropane, at the temperature of 0° C. The results are summarized below.

    ______________________________________                                                  0 wt %      50 wt %                                                   Refrigerant                                                                             evaporated  evaporated  0% change in                                  Composition                                                                             psia    kPa     psia  kPa   vapor pressure                            ______________________________________                                         HFC-32/cyclopropane                                                            83.7/16.3                                                                               126.6   873     126.6 873   0.0                                       99/1     119.7   825     118.9 820   0.7                                       60/40    122.5   845     116.4 803   5.0                                       53/47    120.2   829     108.5 748   9.7                                       52/48    119.8   826     107.1 738   10.6                                      ______________________________________                                    

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants in an ideal vapor compression cycle. The data are based on the following conditions.

    ______________________________________                                         Evaporator temperature                                                                              48.0° F. (8.9° C.)                          Condenser temperature                                                                              115.0° F. (46.1° C.)                         Liquid subcooled to 120° F. (6.7° C.)                            Return Gas           65° F. (18.3° C.)                           ______________________________________                                    

The refrigeration capacity is based on a compressor with a fixed displacement of 3.5 cubic feet per minute and 75% volumetric efficiency. Capacity is intended to mean the change in enthalpy of the refrigerant in the evaporator per pound of refrigerant circulated, i.e. the heat removed by the refrigerant in the evaporator per time. Coefficient of performance (COP) is intended to mean the ratio of the capacity to compressor work. It is a measure of refrigerant energy efficiency.

    __________________________________________________________________________                  Evap.  Cond.             Capacity                                 Refrig.      Press. Press.                                                                               Comp. Dis.  BTU/min                                  Comp.        Psia                                                                              kPa Psia                                                                              kPa                                                                               Temp. °F.                                                                     °C.                                                                        COP                                                                               kw                                       __________________________________________________________________________     HFC-32/isobutane                                                                1.0/99.0    32 221  93                                                                                641                                                                              135   57 4.91                                                                              148                                                                               2.6                                   93.8/6.2     154                                                                               1062                                                                               409                                                                               2820                                                                              205   96 4.32                                                                              605                                                                               10.7                                  99.0/1.0     155                                                                               1069                                                                               416                                                                               2868                                                                              214   101                                                                               4.33                                                                              623                                                                               11.0                                  HFC-32/butane                                                                   1.0/99.0    22 152  68                                                                                469                                                                              137   58 5.03                                                                              110                                                                               1.9                                   99.0/1.0     154                                                                               1062                                                                               413                                                                               2848                                                                              214   101                                                                               4.34                                                                              621                                                                               10.9                                  HFC-32/propylene                                                                1.0/99.0    110                                                                               758 276                                                                               1903                                                                              162   72 4.50                                                                              403                                                                               7.1                                   81.0/19.0    163                                                                               1124                                                                               422                                                                               2910                                                                              197   92 4.25                                                                              609                                                                               10.7                                  99.0/1.0     156                                                                               1076                                                                               418                                                                               2882                                                                              215   102                                                                               4.32                                                                              626                                                                               11.0                                  HFC-32/cyclopropane                                                             1/99        68 469 183                                                                               1262                                                                              175   79 4.89                                                                              299                                                                               5.3                                   85.2/14.8    163                                                                               1124                                                                               425                                                                               2930                                                                              203   95 4.28                                                                              622                                                                               11.0                                  99/1         156                                                                               1076                                                                               419                                                                               2889                                                                              215   102                                                                               4.32                                                                              628                                                                               11.1                                  HFC-125/propylene                                                               1.0/99.0    109                                                                               752 275                                                                               1896                                                                              161   72 4.49                                                                              400                                                                               7.0                                   79.5/20.5    124                                                                               855 318                                                                               2193                                                                              149   65 4.12                                                                              413                                                                               7.3                                   99.0/1.0     128                                                                               883 337                                                                               2324                                                                              144   62 3.84                                                                              401                                                                               7.1                                   HFC-125/cyclopropane                                                            1/99        67 462 180                                                                               1241                                                                              175   79 4.85                                                                              293                                                                               5.2                                   91.3/8.7     133                                                                               917 343                                                                               2365                                                                              147   64 3.92                                                                              421                                                                               7.4                                   99/1         129                                                                               889 340                                                                               2344                                                                              144   62 3.83                                                                              402                                                                               7.1                                   HFC-134/propane                                                                 1.0/99.0    90 621 232                                                                               1586                                                                              150   66 4.52                                                                              336                                                                               5.9                                   52.3/47.7    107                                                                               738 270                                                                               1862                                                                              148   64 4.37                                                                              375                                                                               6.6                                   99.0/1.0     50 345 149                                                                               1020                                                                              150   66 5.04                                                                              243                                                                               4.3                                   HFC-134a/cyclopropane                                                           1/99        66 455 180                                                                               1241                                                                              175   79 4.85                                                                              292                                                                               5.1                                   65.5/34.5    86 593 229                                                                               1579                                                                              159   71 4.61                                                                              344                                                                               6.1                                   99/1         60 414 177                                                                               1220                                                                              151   66 4.69                                                                              269                                                                               4.7                                   HFC-143a/DME                                                                    1.0/99.0    52 357 150                                                                               1034                                                                              168   75 4.91                                                                              243                                                                               4.3                                   90.9/9.1     116                                                                               801 302                                                                               2084                                                                              183   84 4.29                                                                              429                                                                               7.6                                   99.0/1.0     118                                                                               813 322                                                                               2221                                                                              194   90 3.93                                                                              422                                                                               7.4                                   HFC-143a/propylene                                                              1.0/99.0    109                                                                               752 274                                                                               1889                                                                              161   72 4.50                                                                              400                                                                               7.0                                   89.6/10.4    115                                                                               793 298                                                                               2055                                                                              155   68 4.28                                                                              408                                                                               7.2                                   99.0/1.0     115                                                                               793 301                                                                               2075                                                                              155   68 4.24                                                                              406                                                                               7.1                                   HFC-152a/propane                                                                1.0/99.0    89 614 229                                                                               1579                                                                              150   66 4.54                                                                              333                                                                               5.9                                   45.9/54.1    79 545 211                                                                               1455                                                                              156   69 4.63                                                                              317                                                                               5.6                                   99.0/1.0     52 359 156                                                                               1076                                                                              168   76 4.82                                                                              248                                                                               4.4                                   HFC-152a/isobutane                                                              1.0/99.0    31 214  91                                                                                627                                                                              135   57 4.78                                                                              139                                                                               2.4                                   75.5/24.5    49 338 142                                                                                979                                                                              156   69 4.80                                                                              222                                                                               3.9                                   99.0/1.0     52 359 154                                                                               1062                                                                              167   75 4.81                                                                              245                                                                               4.3                                   HFC-152a/butane                                                                 1.0/99.0    21 145  65                                                                                448                                                                              138   59 4.89                                                                              103                                                                               1.8                                   85.0/15.0    45 310 135                                                                                931                                                                              162   72 4.87                                                                              215                                                                               3.8                                   99.0/1.0     51 352 153                                                                               1055                                                                              168   76 4.82                                                                              243                                                                               4.3                                   HFC-152a/cyclopropane                                                           1.0/99.0    66 455 179                                                                               1234                                                                              175   79 4.84                                                                              290                                                                               5.1                                   44.3/55.7    60 414 169                                                                               1165                                                                              173   78 4.83                                                                              272                                                                               4.8                                   99.0/1.0     52 359 155                                                                               1069                                                                              168   76 4.82                                                                              246                                                                               4.3                                   HFC-161/propane                                                                 1.0/99.0    90 621 229                                                                               1579                                                                              150   66 4.53                                                                              334                                                                               5.9                                   44.5/55.5    94 648 244                                                                               1682                                                                              159   71 4.56                                                                              361                                                                               6.4                                   99.0/1.0     83 572 229                                                                               1579                                                                              175   79 4.69                                                                              356                                                                               6.3                                   HFC-161/cyclopropane                                                            1.0/99.0    66 455 178                                                                               1227                                                                              174   79 4.87                                                                              289                                                                               5.1                                   63.4/36.6    75 517 206                                                                               1420                                                                              174   79 4.79                                                                              328                                                                               5.8                                   99.0/1.0     84 579 230                                                                               1586                                                                              174   79 4.70                                                                              357                                                                               6.3                                   HFC-227ca/butane                                                                1.0/99.0    21 145  65                                                                                448                                                                              137   58 4.89                                                                              103                                                                               1.8                                   84.4/15.6    34 234 103                                                                                710                                                                              129   54 4.61                                                                              149                                                                               2.6                                   99.0/1.0     38 262 115                                                                                793                                                                              127   53 4.45                                                                              160                                                                               2.8                                   HFC-227ca/cyclopropane                                                          1.0/99.0    66 455 177                                                                               1220                                                                              174   79 4.88                                                                              289                                                                               5.1                                   55.8/44.2    76 524 202                                                                               1393                                                                              154   68 4.65                                                                              303                                                                               5.3                                   99.0/1.0     40 276 124                                                                                855                                                                              130   54 4.24                                                                              164                                                                               2.9                                   HFC-227ca/DME                                                                   1.0/99.0    52 359 149                                                                               1027                                                                              167   75 4.90                                                                              242                                                                               4.3                                   75.6/24.4    66 455 184                                                                               1267                                                                              142   61 4.48                                                                              260                                                                               4.6                                   99.0/1.0     41 283 122                                                                                841                                                                              128   53 4.49                                                                              170                                                                               3.0                                   HFC-227ca/isobutane                                                             1.0/99.0    31 214  90                                                                                621                                                                              135   57 4.79                                                                              138                                                                               2.4                                   76.8/23.2    36 248 106                                                                                731                                                                              130   54 4.61                                                                              155                                                                               2.7                                   99.0/1.0     38 262 115                                                                                793                                                                              127   53 4.45                                                                              160                                                                               2.8                                   HFC-227ca/propane                                                               1.0/99.0    88 607 226                                                                               1558                                                                              145   63 4.53                                                                              326                                                                               5.7                                   51.6/48.4    76 524 205                                                                               1413                                                                              141   61 4.46                                                                              288                                                                               5.1                                   99.0/1.0     40 276 120                                                                                827                                                                              127   53 4.47                                                                              167                                                                               2.9                                   HFC-227ea/butane                                                                1.0/99.0    21 145  65                                                                                448                                                                              137   58 4.90                                                                              103                                                                               1.8                                   85.8/14.2    34 234 102                                                                                703                                                                              129   54 4.60                                                                              148                                                                               2.6                                   99.0/1.0     37 255 113                                                                                779                                                                              127   53 4.46                                                                              157                                                                               2.8                                   HFC-227ea/cyclopropane                                                          1.0/99.0    66 455 179                                                                               1234                                                                              175   79 4.85                                                                              291                                                                               5.1                                   55.2/44.8    75 517 201                                                                               1386                                                                              154   68 4.61                                                                              300                                                                               5.3                                   99.0/1.0     42 290 125                                                                                862                                                                              128   53 4.45                                                                              173                                                                               3.0                                   HFC-227ea/isobutane                                                             1.0/99.0    31 214  89                                                                                614                                                                              135   57 4.79                                                                              138                                                                               2.4                                   77.6/22.4    36 248 105                                                                                724                                                                              130   54 4.60                                                                              153                                                                               2.7                                   99.0/1.0     38 262 113                                                                                779                                                                              127   53 4.46                                                                              157                                                                               2.8                                   HFC-227ea/propane                                                               1.0/99.0    88 607 226                                                                               1558                                                                              145   63 4.53                                                                              326                                                                               5.7                                   50.4/49.6    76 524 204                                                                               1407                                                                              141   61 4.47                                                                              288                                                                               5.1                                   99.0/1.0     39 269 119                                                                                820                                                                              129   54 4.35                                                                              160                                                                               2.8                                   __________________________________________________________________________

EXAMPLE 5

This Example is directed to measurements of the vapor pressure of the following liquid mixtures of this invention at 25° C.: HFC-32/isobutane; HFC-32/butane; HFC-32/propylene; HFC-125/propylene; HFC-143a/propylene; HFC152a/propane; HFC-152a/isobutane; HFC-152a/butane; HFC-152a/cyclopropane; HFC-161/propane; HFC-161/cyclopropane; HFC-227ca/butane; HFC-227ca/cyclopropane; HFC-227ca/DME; HFC-227ca/isobutane; HFC-227ca/propane; HFC-227ea/butane; HFC-227ea/cyclopropane; HFC-227ea/isobutane; and HFC-227ea/propane. The vapor pressures for these mixtures are shown in FIGS. 1-3, 5 and 9-24.

The vapor pressure data for the graph in FIG. 1 are obtained as follows. A stainless steel cylinder is evacuated, and a weighed amount of HFC-32 is added to the cylinder. The cylinder is cooled to reduce the vapor pressure of HFC-32, and then a weighed amount of isobutane is added to the cylinder. The cylinder is agitated to mix the HFC-32 and isobutane, and then the cylinder is placed in a constant temperature bath until the temperature comes to equilibrium, at which time the vapor pressure of the HFC-32 and isobutane in the cylinder is measured. This procedure is repeated at the same temperature with different weight percents of the components, and the results are plotted in FIG. 1.

Data are obtained in the same way for the mixtures plotted in FIGS. 2, 3, 5 and 9-24.

The data in FIGS. 1-3, 5 and 9-24 show that at 25° C., there are ranges of compositions that have vapor pressures higher than the vapor pressures of the pure components of the composition at that same temperature.

EXAMPLE 6

This Example is directed to the measurements of the vapor pressure of the following liquid mixtures of this invention: HFC-32/cyclopropane; HFC-125/cyclopropane; HFC-134/propane; and HFC-134a/cyclopropane. The vapor pressures of these mixtures were measured at particular compositions as shown by the asterisks in FIG. 4 and 6-8, and a best fit curve was drawn through the asterisks.

The procedure for measuring the vapor pressures for mixtures of HFC-32 and cyclopropane was as follows. A stainless steel cylinder was evacuated, and a weighed amount of HFC-32 was added to the cylinder. The cylinder was cooled to reduce the vapor pressure of HFC-32, and then a weighed amount of cyclopropane was added to the cylinder. The cylinder was agitated to mix the HFC-32 and cyclopropane, and then the cylinder was placed in a constant temperature bath until the temperature came to equilibrium at 0° C., at which time the vapor pressure of the content of the cylinder was measured. This procedure was repeated for various mixtures of HFC-32 and cyclopropane as indicated in FIG. 4.

The data in FIG. 4 show that at 0° C., there are ranges of compositions that have vapor pressures higher than the vapor pressures of the pure components of the composition at that same temperature.

The procedure for measuring the vapor pressure of mixtures of HFC-32/cyclopropane was carried out in the same way for mixtures of HFC-125/cyclopropane, HFC-134/propane and HFC-134a/cyclopropane, except that the measurements of the vapor pressure of mixtures of HFC-134/propane were taken at 15° C. and the measurements of the vapor pressure of mixtures of HFC-34a/cyclopropane were taken at 0.01° C.

Additional Compounds

Other components, such as aliphatic hydrocarbons having a boiling point of -60° to +60° C., hydrofluorocarbonalkanes having a boiling point of -60° to +60° C., hydrofluoropropanes having a boiling point of between -60° to +60° C., hydrocarbon ethers having a boiling point between -60° to +60° C., hydrochlorofluorocarbons having a boiling point between -60° to +60° C., hydrofluorocarbons having a boiling point of -60° to +60° C., hydrochlorocarbons having a boiling point between -60° to +60° C., chlorocarbons and perfluorinated compounds, can be added to the azeotropic or azeotrope-like compositions described above.

Additives such as lubricants, surfactants, corrosion inhibitors, stabilizers, dyes and other appropriate materials may be added to the novel compositions of the invention for a variety of purposes provides they do not have an adverse influence on the composition for its intended application. Preferred lubricants include esters having a molecular weight greater than 250. 

We claim:
 1. An azeotropic or azeotrope-like composition consisting essentially of 66-99 weight percent pentafluoroethane and 1-34 weight percent cyclopropane said composition having a vapor pressure of about 195 psia to about 210 psia when the temperature is adjusted to about 25 degrees C., and wherein when about 50 weight percent of the composition is evaporated at about 25 degrees C., the vapor pressure changes less than about 10 percent.
 2. A composition consisting essentially of about 91.3-99 weight percent pentafluoroethane and about 1-8.7 weight percent cyclopropane wherein the vapor pressure of the composition is higher than the vapor pressure of pentafluoroethane and cyclopropane at 25 degrees C., when the temperature has been adjusted to about 25 degrees C.
 3. A composition consisting essentially of about 44-99 mole percent pentafluoroethane and about 1-56 mole percent cyclopropane wherein the vapor pressure of the composition is higher than the vapor pressure of pentafluoroethane and cyclopropane at 0 degrees C., when the temperature has been adjusted to about 0 degrees C.
 4. A process for producing refrigeration, comprising condensing a composition of claim 1 and thereafter evaporating said composition in the vicinity of the body to be cooled.
 5. A process for producing refrigeration, comprising condensing a composition of claim 2 and thereafter evaporating said composition in the vicinity of the body to be cooled.
 6. A process for producing refrigeration comprising condensing a composition of claim 3, and thereafter evaporating said composition in the vicinity of a body to be cooled.
 7. A process for producing heat comprising condensing a composition of claim 1 in the vicinity of a body to be heated, and thereafter evaporating said composition.
 8. A process for producing heat comprising condensing a composition of claim 2 in the vicinity of a body to be heated, and thereafter evaporating said composition.
 9. A process for producing heat comprising condensing a composition of claim 3 in the vicinity of a body to be heated, and thereafter evaporating said composition. 